Two Black Holes in a Death Spiral: A Stunning Discovery
Imagine witnessing a cosmic dance, a ballet of immense proportions, where two black holes, each with a mass millions of times that of our Sun, are locked in a doomed orbit. This is not a work of fiction, but a groundbreaking discovery made possible by cutting-edge technology and the keen eyes of astronomers.
For the first time, scientists have directly imaged the distinct jets of both black holes in a known binary system, providing concrete evidence for the long-held model of the double core of a galaxy called OJ 287. This galaxy, located a staggering 3.5 billion light-years away, has been a subject of fascination for decades due to the intricate interplay between its two supermassive black holes.
The Power of Quasars
OJ 287 is a quasar, one of the brightest objects in the universe, fueled by the activity of a supermassive black hole at its galactic center. This black hole actively feeds on a vast disk of material, heating it to extreme temperatures and causing it to emit blinding light. However, OJ 287 stands out from other quasars due to its unique characteristics.
A Cosmic Companion
As early as 1982, astronomers noticed that OJ 287's brightness varied with a 12-year periodicity, suggesting the presence of an orbiting companion black hole. This companion, on a strange orbital path, periodically punches through the disk, causing fluctuations in brightness. The model of two black holes circling each other in a 12-year orbit has been a subject of speculation, but now it has been confirmed.
The Dance of the JETS
When black holes devour matter, they can produce powerful jets of particles. In the case of OJ 287, these jets have been observed erupting from the larger black hole, which is an absolute giant, 18 billion times the mass of the Sun. However, the detection of a jet from the smaller black hole, at a more modest 150 million solar masses, had remained elusive until now.
A Technological Triumph
Astronomers used a very long baseline interferometer called RadioAstron to capture the sharpest observations of OJ 287 in 2014. This space-based observatory, working in conjunction with Earth-based antennas, achieved a record-breaking resolution, allowing scientists to pick out structures 3.5 billion light-years away, equivalent to imaging a coin on the surface of the Moon.
Unraveling the Mystery
By analyzing the RadioAstron data, researchers identified features associated with the astrophysical jet from the feeding black hole. They also calculated how the motion of the secondary black hole would affect the path of its jet, predicting a twisted, rotating pattern. When they compared these predictions with previous models of binary black hole behavior, they found a remarkable match.
The Image Unveiled
In the image, the main jet streams diagonally across the galactic core, while a fainter, angled streak reveals the predicted path of the smaller black hole's jet. The Doppler properties of the jets suggest that the secondary jet is moving more slowly, about half the speed of the primary jet.
A Historic Discovery
The RadioAstron images, obtained nearly a decade ago, provide the first direct evidence of two astrophysical jets, each erupting from a separate supermassive black hole. This discovery opens up new avenues for research, with the next step being the verification of the finding through further observations.
The team's research has been published in The Astrophysical Journal, marking a significant milestone in our understanding of black hole interactions and the complex dynamics of the universe.
